1 /* 2 * fs/sysfs/sysfs.h - sysfs internal header file 3 * 4 * Copyright (c) 2001-3 Patrick Mochel 5 * Copyright (c) 2007 SUSE Linux Products GmbH 6 * Copyright (c) 2007 Tejun Heo <teheo@suse.de> 7 * 8 * This file is released under the GPLv2. 9 */ 10 11 #include <linux/lockdep.h> 12 #include <linux/kobject_ns.h> 13 #include <linux/fs.h> 14 #include <linux/rbtree.h> 15 16 struct sysfs_open_dirent; 17 18 /* type-specific structures for sysfs_dirent->s_* union members */ 19 struct sysfs_elem_dir { 20 unsigned long subdirs; 21 /* children rbtree starts here and goes through sd->s_rb */ 22 struct rb_root children; 23 }; 24 25 struct sysfs_elem_symlink { 26 struct sysfs_dirent *target_sd; 27 }; 28 29 struct sysfs_elem_attr { 30 const struct kernfs_ops *ops; 31 struct sysfs_open_dirent *open; 32 }; 33 34 struct sysfs_inode_attrs { 35 struct iattr ia_iattr; 36 void *ia_secdata; 37 u32 ia_secdata_len; 38 }; 39 40 /* 41 * sysfs_dirent - the building block of sysfs hierarchy. Each and 42 * every sysfs node is represented by single sysfs_dirent. 43 * 44 * As long as s_count reference is held, the sysfs_dirent itself is 45 * accessible. Dereferencing s_elem or any other outer entity 46 * requires s_active reference. 47 */ 48 struct sysfs_dirent { 49 atomic_t s_count; 50 atomic_t s_active; 51 #ifdef CONFIG_DEBUG_LOCK_ALLOC 52 struct lockdep_map dep_map; 53 #endif 54 struct sysfs_dirent *s_parent; 55 const char *s_name; 56 57 struct rb_node s_rb; 58 59 union { 60 struct completion *completion; 61 struct sysfs_dirent *removed_list; 62 } u; 63 64 const void *s_ns; /* namespace tag */ 65 unsigned int s_hash; /* ns + name hash */ 66 union { 67 struct sysfs_elem_dir s_dir; 68 struct sysfs_elem_symlink s_symlink; 69 struct sysfs_elem_attr s_attr; 70 }; 71 72 void *priv; 73 74 unsigned short s_flags; 75 umode_t s_mode; 76 unsigned int s_ino; 77 struct sysfs_inode_attrs *s_iattr; 78 }; 79 80 #define SD_DEACTIVATED_BIAS INT_MIN 81 82 #define SYSFS_TYPE_MASK 0x00ff 83 #define SYSFS_DIR 0x0001 84 #define SYSFS_KOBJ_ATTR 0x0002 85 #define SYSFS_KOBJ_BIN_ATTR 0x0004 86 #define SYSFS_KOBJ_LINK 0x0008 87 #define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK) 88 #define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR) 89 90 #define SYSFS_FLAG_MASK ~SYSFS_TYPE_MASK 91 #define SYSFS_FLAG_NS 0x01000 92 #define SYSFS_FLAG_REMOVED 0x02000 93 #define SYSFS_FLAG_HAS_SEQ_SHOW 0x04000 94 #define SYSFS_FLAG_HAS_MMAP 0x08000 95 96 static inline unsigned int sysfs_type(struct sysfs_dirent *sd) 97 { 98 return sd->s_flags & SYSFS_TYPE_MASK; 99 } 100 101 #ifdef CONFIG_DEBUG_LOCK_ALLOC 102 103 #define sysfs_dirent_init_lockdep(sd) \ 104 do { \ 105 struct attribute *attr = sd->priv; \ 106 struct lock_class_key *key = attr->key; \ 107 if (!key) \ 108 key = &attr->skey; \ 109 \ 110 lockdep_init_map(&sd->dep_map, "s_active", key, 0); \ 111 } while (0) 112 113 /* Test for attributes that want to ignore lockdep for read-locking */ 114 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) 115 { 116 struct attribute *attr = sd->priv; 117 int type = sysfs_type(sd); 118 119 return (type == SYSFS_KOBJ_ATTR || type == SYSFS_KOBJ_BIN_ATTR) && 120 attr->ignore_lockdep; 121 } 122 123 #else 124 125 #define sysfs_dirent_init_lockdep(sd) do {} while (0) 126 127 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd) 128 { 129 return true; 130 } 131 132 #endif 133 134 /* 135 * Context structure to be used while adding/removing nodes. 136 */ 137 struct sysfs_addrm_cxt { 138 struct sysfs_dirent *removed; 139 }; 140 141 /* 142 * mount.c 143 */ 144 145 /* 146 * Each sb is associated with one namespace tag, currently the network 147 * namespace of the task which mounted this sysfs instance. If multiple 148 * tags become necessary, make the following an array and compare 149 * sysfs_dirent tag against every entry. 150 */ 151 struct sysfs_super_info { 152 void *ns; 153 }; 154 #define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info)) 155 extern struct sysfs_dirent sysfs_root; 156 extern struct kmem_cache *sysfs_dir_cachep; 157 158 /* 159 * dir.c 160 */ 161 extern struct mutex sysfs_mutex; 162 extern spinlock_t sysfs_symlink_target_lock; 163 extern const struct dentry_operations sysfs_dentry_ops; 164 165 extern const struct file_operations sysfs_dir_operations; 166 extern const struct inode_operations sysfs_dir_inode_operations; 167 168 struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd); 169 void sysfs_put_active(struct sysfs_dirent *sd); 170 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt); 171 void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name); 172 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, 173 struct sysfs_dirent *parent_sd); 174 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, 175 struct sysfs_dirent *parent_sd); 176 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt); 177 178 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, 179 const unsigned char *name, 180 const void *ns); 181 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type); 182 183 void release_sysfs_dirent(struct sysfs_dirent *sd); 184 185 static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd) 186 { 187 if (sd) { 188 WARN_ON(!atomic_read(&sd->s_count)); 189 atomic_inc(&sd->s_count); 190 } 191 return sd; 192 } 193 #define sysfs_get(sd) __sysfs_get(sd) 194 195 static inline void __sysfs_put(struct sysfs_dirent *sd) 196 { 197 if (sd && atomic_dec_and_test(&sd->s_count)) 198 release_sysfs_dirent(sd); 199 } 200 #define sysfs_put(sd) __sysfs_put(sd) 201 202 /* 203 * inode.c 204 */ 205 struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd); 206 void sysfs_evict_inode(struct inode *inode); 207 int sysfs_permission(struct inode *inode, int mask); 208 int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); 209 int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, 210 struct kstat *stat); 211 int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, 212 size_t size, int flags); 213 int sysfs_inode_init(void); 214 215 /* 216 * file.c 217 */ 218 extern const struct file_operations kernfs_file_operations; 219 220 int sysfs_add_file(struct sysfs_dirent *dir_sd, 221 const struct attribute *attr, int type); 222 223 int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, 224 const struct attribute *attr, int type, 225 umode_t amode, const void *ns); 226 void sysfs_unmap_bin_file(struct sysfs_dirent *sd); 227 228 /* 229 * symlink.c 230 */ 231 extern const struct inode_operations sysfs_symlink_inode_operations; 232 int sysfs_create_link_sd(struct sysfs_dirent *sd, struct kobject *target, 233 const char *name); 234